Extension Tubes for Sigma 180 Ex 3.5

Hi there,

Can anyone help me with this issue. Which brand is the more suitable for canon fitting? And which one? Im looking for quality vs magnification, a reasonable balance between both.

Thanks in advanced
Paulo A.Lopes

Extension tubes are one of the few pieces of equipment where the brand really doesn't matter. All they are are tubes with electrical connections running between them - no glass.

Any brand that is compatible with Canon EOS equipment will work. Canon's obviously, but they are expensive. Kenko is a fairly popular third party brand for this as well and their set of three runs about the price of Canon's 25 mm tube (or at least it used to be about that price).

They come in plastic????? Yeah, that can't be a good idea for reliability or sharpness.

Steve, thanks for bringing that to my attention.

Thanks! Im going to the set of Kenko.

Paulo, you might want to check with people who have used extension tubes with the Sigma 180, because the effect of the tube decreases as the focal length of the lens increases. So using an extension tube with your 180-mm lens will not have nearly the effect it does when it's used on a 60-mm macro lens. Another option--that does not increase exposure times as tubes do--is a high-quality diopter auxililary lens. Raynox makes several, and they are multi-element, coated lenses that produce excellent image quality. This link is to a two-lens set. Their most powerful would make your 180 into a microscope!

One more time thanks. I m not really looking for magnification, only something that approaches the lens to the subject. Its true that the Ext.Tubes reduces DOF considerably and sure they will increase magnification. With this two options that NPM members write, witch one ? 180 Sigma closest focus is about 46 cm to the subject. My main goal is to decrease that focus to about 30 cm minimum and 20 cm maximum. Do you think that the Kenkos set or the single tube can do the job properly?

Thanks